I. Field of the Invention
The present invention relates generally to printed wiring boards, and is particularly concerned with an EMI (electromagnetic interference) shield apparatus for printed wiring boards to shield components on the board from noise emanating from other components.
II. Description of the Related Art
EMI shields are generally rectangular frames with an integral or separate cover. The frames are placed at appropriate positions on a printed wiring board during assembly in order to enclose areas containing components to be shielded from one another. Typically, dots of solder material are placed on the board surrounding rectangular areas containing components to be shielded, and the EMI shields or frames are seated onto the dots. The assembly is then passed through a reflow oven to soften the solder material and adhere the EMI shields to the board. In a typical layout, several rectangular shields will be placed on the board, each having one or more walls in face to face engagement with a wall of an adjacent shield. One problem with such arrangements is the footprint or area taken up by the EMI frames, particularly with the current tendency towards smaller and smaller printed wiring boards.